In the related art, for example, as a pressure sensor which detects variation in pressures, a pressure sensor is known which includes a substrate which has a gap portion inside the substrate, a diaphragm portion which configures a portion of an inner wall of the gap portion, and a pressure-sensitive element such as a piezoresistor which is provided on the surface of the diaphragm portion (for example, refer to PTL 1).
According to this pressure sensor, an electrical resistance of the pressure-sensitive element is changed according to a magnitude of deformation of the diaphragm portion due to an external pressure. As a result, the pressure sensor can detect a pressure applied to the diaphragm portion on the basis of a voltage change generated in the pressure-sensitive element.